Rabu, 30 Maret 2011

Star topologies is very different from the bus topology or ring topology that hard in improving its network. star topologies is better than the both of topologies earlier.

Star topology is centralized and likened topologies similiar to the star. In a star topology, all the cables from computers connected to a central location, where everything is connected to a device called hub.

Star topology is used in dense networks, while endpoint can be reached directly from a central location, the need for network expansion, and requires high reliability. This topology is the arrangement that using more cable than bus and because of all the computers and devices connected to a central point. So if there is one computer or device that is corrupt, the other will not affect the network.

How Star Network Work?

Every computer in star network to communicate with central hub that sends back messages to all computers (in a broadcast star network) or only to the destination computer (in switched star network). Hub of a broadcast star network can be active or passive. Active hub renew the electrical signal that is received and sends it to all computers connected to the hub. Hub types are often also called multiport repeater. If we use the hub has 32 ports, if all ports filled, then the collision will often occur that would result in decreased of network performance. To avoid this we can use a switch that has the ability to define an destination data. Active hub and switch requires power to run it. Pasisive hubs, like wiring panels or punch-down block, only serves as a connection point (connection point) and did not renew the reinforcement signal or signals. Passive hubs do not requires electricity to run it.

Sabtu, 26 Maret 2011

afterpreviouslytalking aboutbustopology,nowI'mtryingtowriteanothertopologyisa ring topology. ring topology is a concept to build a network that forms a circular pattern like a ring. To form a ring topology, each must be connected centra

l series with each other and this relationship will form a closed loop. In this system each central must be designed to interact with the adjacent central and far apart. Thus the ability to switch to different central direction.

The advantage of this network topology, among others: the level of network complexity is low (simple), also if there is any interference or damage to the central flow traffic can be passed in the other direction in sistem.Yang most widely used in computer networks is a network of buses and tree type, it is because of their complexity, ease of installation and maintenance as well as the price paid. But only just a tree-type network reliability that is recognized as loss one of the wires on the client, will not affect relations with other clients.

Ring topology is used in a network that has a high performance, which requires network bandwidth for time-sensitive features such as video and audio, or when performance is needed when the computer is connected to the network in large quantities.

How it works

Every computer connected to the natural next computerring, and each computer sends what is received from the previous computer. The messages flowing through ring inone direction. Every computer that sends what it receives,the ring is an active network. There is no end to the ring.Some do token passing ring network. Short message, called token ring to run through a computer wants to sendinformation to another computer. The computer then converts these tokens, by adding the address and adddata, and send it through the ring. Then each computer in order to receive the token and send the information to thecomputer next to the computer with the address of thetarget achieved or token back to the sender computer(original sender of the message). Computers recipientswill reply message to the sender of the message homeindicates that the message has been received. Then theoriginal sender of the message will make another tokenand put it on the network, and the token will continue tospin until there is another computer that captures the tokenand ready to start delivery.

Benefits of using ring topology:

• There is no monopoly on computer network, becauseevery computer has the right to equal access to the token.

• Data flows in one direction so that the collision can beavoided.

lack of using Ring Topology

* If there is one computer in the ring that failed to function, it will affect the whole network.

• It is difficult to overcome the damage in a network thatuses ring topology.

Jumat, 25 Maret 2011

Topology is an description of communication between devices in series of computer. If 2 or more Nod connected hybrid topology is formed. There are three types of topology principle in a LAN , Bus, Ring and Star topologies. There Other topologies such as hybrid, mesh and wireless.

BUS TOPOLOGY

topology bus is a LAN topology for a small scale. with the following specifications:

a. Interface

Interfaces for bus topology is to use passive equipment or T connector. This equipment does not have the ability to strengthen or repeat signal in the transfer. Accordingly the way, more further data / signal to move, so the weaker signal in the network.

b. Multipoint Connection Bus topology has a multipoint connection where a conductive medium in partnership by all Nod. What are the data that the transfer will be in partnership by all Nod.

c. Addressing

This topology justify unicast, multicast and broadcast addressing. Each Nod will listen and check the recipient address on the received frame. If a unicast address, Nod will check address on the frame. If the frontier of Nod will receive the data if not, the frame will be discarded. If the multicast address, Nod involved in group will take the data and unrelatedNod will discard the frame. If the broadcast address, all Nod will save frames in transfer.

2.tomaintaininformationin order to remainreliableandup to date: that iscentralizeddatastoragesystemmanagedbybaiallowallusersaccess datafromdifferent locations,andrestrictaccess todatawhendataisbeingprocessed.

Sabtu, 19 Maret 2011

aftera fewdaysago post about the NIC which is a component that converts data into electrical signals, so now I will discuss about the data that are Conductor cable network. network cable is divided into several types. that are:

1. Coaxial cable:

probably a bit difficult to find a network that still uses this cable. because the coaxial cable used by a computer network with bus topology type. positions lined up the other end, if there is damage, it will disrupt the overall network.bus topology has several weaknesses that make the performance less effective. them if a server in the store at the end of the network and client Thereare 2 types ofcoaxialcable.that are:

a. Thicknet

b. thinnet

2. UTP (unshielded twisted pair):

This cable has 8 wires in it that has a small role re

spectively.

role on the cable is determined by the RJ-45 connectors that connect to the NIC. This cable is suitable for star topology type that connects a computer to a

switch or hub that terhubungn with

another computer. This cable is used on any computer network at this

time. because the star topology is very easy in the diagnosis of damage and easy to fix. and jka there is damage on one cable that connects the computer, it will not affect the overall computer network and This cable can deliver data up to 100 m.

3. STP (shielded twisted pair)

STP (Shielded twisted pair) is a type of telephone cable that is used in some installations business. There is an additional

wrapper for each pair cable ("twisted pair"). STP cable is also used for data networks, use on the IBM Token-Ring. Packaging can provide better protection against EMI interference. These cables are usually used in token ring topology. will however have some disadvantages. that:

a. Expensive price

b. At high frequencies, the balance down so it can not compensate for the emergence of "crosstalk" and signal "noise".

4. FO (Fiber Optic):

Fiber Optic Cable is the latest cable technology. Made of optical glass. In the middle there is a cable glas filaments, called "core", and surrounded by a layer of "cladding", "buffer coating", the amplifier material, and protector luar.Informasi transmitted using light waves by converting electrical signals into light waves. The most used transmitter LED or laser. and has several benefits there are:

a. Large bandwidth capacity (gigabits per second).

b. Further transmission distance (2 to more than 60 kilometers).

c. Immune to electromagnetic interference.

Fiber Optic Cables are widely used in WAN networks for voice and data communications. The main obstacle in the use of fiber optic cable LAN is an electronic device that is still expensive. While the price of fiber optic cable itself is comparable with UTP LAN cable.

Minggu, 13 Maret 2011

NIC (network interface card) or usually called a LAN card is an additional interface card on a computer that has a function as modifiers electricity into digital data or opposite. if you want to connect multiple computers using a cable, then each computer must have a NIC as a gateway out of the entry of data in a local area network. There are two types of NIC, onboard NIC and external NIC .

1. onboard NIC , is the NIC that integrates with the mainboard and can not be separated.

2. External NICs: an optional NIC is installed if the onboard NIC does not exist. External NICs installed in PCI slots, so you can add as many PCI slots are available.

with each other NIC you can connect with multiple computers and became a small-scale computer network called LAN (Local Area Network). in addition to the computer, you also can connect with a printer that can be used together, sharing files, even you can share the device.

Sabtu, 12 Maret 2011

Now, Laptops have become one of the main priorities can be equated with even handphone. but since this laptop is a portable electronic goods, so it is very vulnerable to theft of a laptop.

solution is to insure your laptop on the company providing insurance services laptop. many insurance providers online with low cost laptops. would not hurt if you insure your laptop because it will provide many benefits to the secure of your laptop. you include your laptop safe from theft of laptops, the damage resulting from disasters such as floods, and accidents. even if that happens, you will your insurance company will replace it with a new laptop within 48 hours.

Laptop insurance company can guarantee your safety latptop with excellent service and handle your laptop problems quickly. so what are you waiting? your laptop insured immediately prior to the above things happen to your laptop without you knowing when it will happen.

Kamis, 10 Maret 2011

World of Warcraft (WoW), who does not know with this game? This game is very famous among lovers of the game. but for newbies gamers, will be quite difficult to follow this game. then, you need to find wow guide who can guide you in playing world of warcraft. wow guides will guide you in making the strategy, build, and others. world of warcraft guide is very helpful for newbies gamers. you can quickly become a master world of warcraft by following the world of warcraft guides.

Selasa, 08 Maret 2011

Today, the computer is an absolute tool of its existence and become a necessity in everyday life. but have you insure your computer? computer insurance is very important for people who have important data inside the computer. computer insurance will protect all the bad things that will happen on your computer.

computer insurance protection can be divided into some sections. there are:

1.Computer Hardware insurance that protects your computer hardware from damage or theft. compensation that would have got is something that you agree when you register your computer on a computer insurance providers.

2.insurance computer software that protects your data from any damages that occur on your computer software. although the price for software is quite expensive insurance, but please take into account how important and valuable data that your computer have?

3.lost computer, if there is theft of computer / laptop.

several benefits that will you can if you insure your computer, you will definitely calm them, because your computer will be protected from any risk arising from accident, disaster or things that happen beyond our expectations which can cause your computer to be damaged or lost .

we never know when it will happen something bad had happened to us, especially our computer.

before you insure your computer, you should compare various computer insurance providers, to review further the advantages and disadvantages of the service provider computer insurance. this is done to minimize risks that occur on our computers. and also secure your computer from all the bad things that could happen happened to you.

so, what are you waiting? immediately insure your computer before bad things happen to your computer and its hardware and software.

This world would be destroyed, all places will be razed to the ground, and all believers will be the end of the Hour that life on earth. and will begin a lasting kahidupan after the apocalypse. Christians believe that there will be an event called The Rapture of the Church. no one knows when these events will occur. only god knows when this event occurred.

as people we just hope that there will be apparent that the best thing for all people on earth.